1.   Commodities advisers are not only fingerprinted and investigated, but must divulge subscriber lists and endure on-the-spot audits, according to Bullock.

2.   None of the companies involved in space tourism will divulge their lists of potential clients.

3.   Online booksellers can be forced to divulge lists of customers who have expressed interest in books about explosives, poisons or other subjects that arouse suspicion.

4.   He also backed the decision not to divulge the list.